COMPARISON OF INDUCED AND INDEPENDENT MAJOR DEPRESSIVE-DISORDERS IN 2,945 ALCOHOLICS

Objective: Depressive episodes among alcohol-dependent men and women a re heterogeneous in causation and clinical course. This study, tested three hypotheses regarding the rates and clinical characteristics of t wo potential subtypes of these affective states: those that appear to be substance-induced mood disorders and those that ave independent maj or depressive episodes. Method: Semistructured, detailed interviews we re administered to 2,945 alcohol-dependent subjects as part of the Col laborative Study on the Genetics of Alcoholism. With the use of a time line method for determining the type of mood disorder among probands, relatives, and comparison subjects, individuals with histories of the two types of mood disorders were compared. Results: Major depressive episodes with an onset before the development of alcohol dependence or during a subsequent long abstinence period (i.e., independent depress ions) were observed in 15.2% of the alcoholics, while 26.4% reported a t least one substance-induced depressive episode. According to a logis tic regression analysis, the subjects with independent (as compared to substance-induced) major depressive episodes were more likely to be m arried Caucasian, and female, to have had experience with fewer drugs and less treatment for alcoholism, to have attempted suicide, and, on the basis of personal interviews with family members, to have a close relative with a major mood disorder. Conclusions: These results suppor t the contention that it is possible to differentiate between what app ear to be substance-induced and independent depressive episodes in alc oholics. Such differentiation might be important for establishing prog nosis and optimal treatment.